Systems and methods for electrosurgical prevention of disc herniations

Abstract

The present invention provides systems and methods for selectively applying electrical energy to a target location within a patient's body, particularly including tissue in the spine. The present invention applies high frequency (RF) electrical energy to one or more electrode terminals in the presence of electrically conductive fluid or saline-rich tissue to contract collagen fibers within the tissue structures. In one aspect of the invention, a system and method is provided for contracting a portion of the nucleus pulposus of a vertebral disc by applying a high frequency voltage between an active electrode and a return electrode within the portion of the nucleus pulposus, where contraction of the portion of nucleus pulposus inhibits migration of the portion nucleus pulposus through the fissure.

What is claimed is: 
     
       1. A method for inhibiting herniation and/or reherniation of a vertebral disc, the vertebral disc including an annulus fibrosus, a nucleus pulposus, and at least one fissure in the annulus fibrosus, the method comprising:
 positioning a distal end of a shaft of an electrosurgical probe into the disc, the probe having a plurality of electrodes coupled to a high frequency power supply, the plurality of electrodes comprising at least one active electrode and at least one return electrode, the active electrode being disposed towards the distal end of the shaft; 
 positioning at least one active electrode within a portion of the nucleus pulposus, the portion being adjacent to and/or in contact with the fissure; 
 contracting the portion of nucleus pulposus by applying a high frequency voltage between the at least one active electrode and the at least one return electrode within the portion of the nucleus pulposus, whereby the contraction coagulates the portion of the nucleus pulposus and inhibits migration of the portion nucleus pulposus through the fissure; and 
 inserting an implant material between the contracted portion of the nucleus pulposus and the fissure in the annulus fibrosus, thereby improving stability of the disc, and inhibiting migration of the nucleus pulposus through the fissure. 
 
     
     
       2. The method of  claim 1 , further comprising ablating or vaporizing a portion of the nucleus pulposus. 
     
     
       3. The method of  claim 2 , wherein ablating or vaporizing a portion of the nucleus pulposus occurs prior to the act of contracting the portion of nucleus pulposus. 
     
     
       4. The method of  claim 2 , wherein ablating or vaporizing a portion of the nucleus pulposus occurs subsequent or contemporaneous to the act of contracting the portion of nucleus pulposus. 
     
     
       5. The method of  claim 2 , wherein the electrosurgical probe is a first electrosurgical probe, and a second electrosurgical probe is used for ablating or vaporizing the nucleus pulposus, where the first electrosurgical probe is not adapted to ablate and/or vaporize. 
     
     
       6. The method of  claim 2 , wherein the act of ablating or vaporizing nucleus pulposus of the disc further comprises placing an electrically conductive medium in contact with the active and return electrodes. 
     
     
       7. The method of  claim 6 , wherein ablating or vaporizing nucleus pulposus comprises generating electric field intensities between the at least one active electrode and at least one return electrode such that the electric field intensities are sufficient to vaporize at least a portion of the conductive medium in contact with one of the active electrodes. 
     
     
       8. The method of  claim 6 , where placing an electrically conductive medium comprises providing an electrically conductive fluid into the disc. 
     
     
       9. The method of  claim 6 , where placing an electrically conductive medium comprises providing an electrically conductive gel onto the distal end of a shaft. 
     
     
       10. The method of  claim 6 , where the conductive medium comprises saline rich tissue of the disc. 
     
     
       11. The method of  claim 6 , further comprising aspirating at least a portion of the conducting medium. 
     
     
       12. The method of  claim 1 , where the implant material comprises a material selected from the group consisting of a metal, ceramic, polyurethane, hydrogel, protein hydrogel, thermopolymer, adhesive, collagen, and fibrogen glue. 
     
     
       13. The method of  claim 1 , further comprising inserting a sealant into the disc. 
     
     
       14. The method of  claim 13 , wherein the sealant is selected from a group consisting of an adhesive, collagen, a polyurethane, hydrogel, thermopolymer, a ceramic, a metal, and fibrogen glue. 
     
     
       15. The method of  claim 1 , wherein electrosurgical probe comprises a tissue treatment surface which contains at least the active electrodes. 
     
     
       16. The method of  claim 15 , where the tissue treatment surface is curved and adapted to treat the interior of the disc. 
     
     
       17. The method of  claim 15 , where the tissue treatment surface has an axial length and a thickness substantially less than the axial length and a width substantially larger than said thickness to form a substantially planar body having an active side and a non-active side opposing the active side, wherein at least the active electrodes are on the active side. 
     
     
       18. The method of  claim 1 , where the shaft is curved. 
     
     
       19. The method of  claim 1 , wherein the at least one return electrode is located towards a distal end of the shaft. 
     
     
       20. The method of  claim 1 , wherein the at least one return electrode is located on the outer surface of the patient's body. 
     
     
       21. The method of  claim 1 , wherein the at least one active electrode comprises a single, active electrode at the distal end of a shaft. 
     
     
       22. The method of  claim 1 , wherein the at least one active electrode comprises a plurality of electrically isolated active electrodes at the distal end of a shaft. 
     
     
       23. The method of  claim 1 , further comprising independently controlling current flow from the at least one active electrode based on impedance between the electrodes. 
     
     
       24. The method of  claim 1 , wherein the at least one return electrode is axially spaced on the shaft from the at least active electrode. 
     
     
       25. The method of  claim 1 , wherein the positioning step comprises introducing at least a distal portion of the electrosurgical probe through a percutaneous penetration in a patient. 
     
     
       26. The method of  claim 25 , wherein the percutaneous penetration is located on the patient's back, abdomen, or thorax. 
     
     
       27. The method of  claim 1 , wherein the positioning step comprises introducing at least a distal portion of the electrosurgical probe anteriorly through the patient to the spine. 
     
     
       28. The method of  claim 1 , wherein the act of positioning comprises advancing the distal end of the shaft through an existing opening in the annulus fibrosus. 
     
     
       29. The method of  claim 28 , wherein the existing opening comprises the fissure in the annulus. 
     
     
       30. The method of  claim 1 , wherein the act of positioning comprises advancing the distal end of the shaft through a wall of the annulus fibrosus. 
     
     
       31. The method of  claim 1 , wherein the contracting act causes the portion of nucleus pulposus to be heated to a temperature in the range of from about 45° C. to 90° C. 
     
     
       32. The method of  claim 31 , wherein the contracting act causes the portion of nucleus pulposus to be heated to a temperature in the range of from about 60° C. to 70° C. 
     
     
       33. A method for inhibiting herniation and/or reherniation of a vertebral disc, the vertebral disc including an annulus fibrosus having a fissure therein, and a nucleus pulposus, the method comprising:
 positioning a distal end of a shaft of an electrosurgical probe into the disc, the probe having a plurality of electrodes coupled to a high frequency power supply, the plurality of electrodes comprising at least one active electrode and at least one return electrode, the active electrode being disposed towards the distal end of the shaft; 
 positioning the at least one active electrode within a portion of the nucleus pulposus; 
 contracting the portion of nucleus pulposus by applying a high frequency voltage between the at least one active electrode and the at least one return electrode within the portion of the nucleus pulposus, whereby the contraction coagulates the portion of the nucleus pulposus; and 
 inserting an implant material between the contracted portion of the nucleus pulposus and the fissure in the annulus fibrosus, thereby improving stability of the disc and inhibiting migration of the nucleus pulposus through the fissure in the annulus fibrosus. 
 
     
     
       34. The method of  claim 33 , further comprising ablating or vaporizing a portion of the nucleus pulposus. 
     
     
       35. The method of  claim 34 , wherein the act of ablating or vaporizing nucleus pulposus of the disc further comprises placing an electrically conductive medium in contact with the active and return electrodes. 
     
     
       36. The method of  claim 33 , wherein the positioning step comprises introducing at least a distal portion of the electrosurgical probe through a percutaneous penetration in a patient. 
     
     
       37. The method of  claim 36 , wherein the percutaneous penetration is located on the patient's back, abdomen, or thorax. 
     
     
       38. The method of  claim 37 , wherein the step of positioning the distal end of the shaft comprises advancing the distal end of the shaft through an existing opening in the annulus fibrosus and wherein the existing opening comprises the fissure in the annulus. 
     
     
       39. The method of  claim 33 , wherein the positioning step comprises introducing at least a distal portion of the electrosurgical probe anteriorly through the patient to the spine. 
     
     
       40. The method of  claim 33 , wherein the act of positioning comprises advancing the distal end of the shaft through an existing opening in the annulus fibrosus. 
     
     
       41. The method of  claim 33 , wherein the act of positioning comprises advancing the distal end of the shaft through a wall of the annulus fibrosus. 
     
     
       42. The method of  claim 33 , wherein the contracting act causes the portion of nucleus pulposus to be heated to a temperature in the range of from about 45° C. to 90° C. 
     
     
       43. The method of  claim 33 , wherein the implant material comprises a material selected from the group consisting of a metal, ceramic, polyurethane, hydrogel, protein hydrogel, thermopolymer, adhesive, collagen, and fibrogen glue. 
     
     
       44. A method for treating a herniated vertebral disc, the vertebral disc comprising an annulus fibrosus having a fissure therein and a nucleus pulposus, the method comprising:
 positioning a distal end of a shaft of an electrosurgical probe into a herniated portion of the disc, the probe having a plurality of electrodes coupled to a high frequency power supply, the plurality of electrodes comprising at least one active electrode and at least one return electrode, the active electrode being disposed towards the distal end of the shaft; 
 positioning the at least one active electrode within the herniated portion of the nucleus pulposus; 
 contracting the nucleus pulposus .by applying a high frequency voltage between the at least one active electrode and the at least one return electrode, whereby the contraction relieves the herniation and creates a space between the nucleus and annulus; and 
 inserting an implant material between the nucleus and the fissure, thereby improving stability of the disc and inhibiting migration of the nucleus pulposus through the fissure. 
 
     
     
       45. The method of  claim 44 , further comprising ablating or vaporizing a portion of the nucleus pulposus. 
     
     
       46. The method of  claim 45 , wherein the act of ablating or vaporizing nucleus pulposus of the disc further comprises placing an electrically conductive medium in contact with the active and return electrodes. 
     
     
       47. The method of  claim 44 , wherein the positioning step comprises introducing at least a distal portion of the electrosurgical probe through a percutaneous penetration in a patient. 
     
     
       48. The method of  claim 47 , wherein the percutaneous penetration is located on the patient's back, abdomen, or thorax. 
     
     
       49. The method of  claim 44 , wherein the positioning step comprises introducing at least a distal portion of the electrosurgical probe anteriorly through the patient to the spine. 
     
     
       50. The method of  claim 44 , wherein the act of positioning comprises advancing the distal end of the shaft through an existing opening in the annulus fibrosus. 
     
     
       51. The method of  claim 50 , wherein the existing opening comprises the fissure in the annulus. 
     
     
       52. The method of  claim 44 , wherein the act of positioning comprises advancing the distal end of the shaft through a wall of the annulus fibrosus. 
     
     
       53. The method of  claim 44 , wherein the contracting act causes the portion of nucleus 8 pulposus to be heated to a temperature in the range of from about 45° C. to 90° C. 
     
     
       54. The method of  claim 44 , wherein the implant material comprises a material selected from the group consisting of a metal, ceramic, polyurethane, hydrogel, protein hydrogel, thermopolymer, adhesive, collagen, and fibrogen glue.